Self-refrigerating packaging and associated actuation device

ABSTRACT

The invention relates to self-refrigerating beverage packaging comprising: a first cavity ( 10 ) which contains a beverage; a second cavity ( 20 ) which forms a heat exchanger and which contains a refrigerating liquid and the vapour thereof; a third cavity ( 30 ) which contains means for the adsorption pumping of said vapour and means of connecting ( 40 ) the second cavity with the third cavity. The inventive packaging is characterised in that the second and third cavities are provided with a common wall ( 25 ) comprising the built-in connection means, and in that said connection means ( 40 ) comprise a check valve ( 42 ) which can withstand pressure exerted on the side of the second cavity and which opens under the effect of a force exerted on the side of the third cavity.

BACKGROUND OF THE INVENTION

The present invention relates to a container which allows its contentsto be cooled by an evaporation and adsorption method. The principle of asuch a cooling method consists of evaporating a liquid, calledrefrigerant, under the action of a depression maintained by pumping thevapors of said liquid. The invention applies to the cooling of foodproducts such as beverages, ice creams, but also to non-food productssuch as pharmaceuticals or cosmetics.

The invention applies quite particularly to the cooling of a beveragecontained in a closed container of can or bottle type.

An aim of the present invention is therefore to allow the consumption ofa beverage at an ideal temperature in any place and at any time.

The implementation of the method of cooling by evaporation andadsorption is known and has been the subject of numerous researchprogrammes in the prior art. Numerous devices have been proposed,combining a heat exchanger containing a liquid to be evaporated with areservoir containing an adsorbent, in particular for applications toself-cooling beverage containers.

Thus, U.S. Pat. No. 4,928,495, an illustration of which is given in FIG.1, discloses a self-cooling container configuration 10 (presented as acan) comprising a heat exchanger 16 of flattened rectangular shapeimmersed in a beverage to be cooled and connected to an adsorptiondevice 22. This patent discloses an outline scheme without specifyingthe means of producing such a device taking account of the economicconstraints associated with an application to disposable containers.

Moreover, International Patent Application WO 01/11297, an illustrationof which is given in FIG. 2 a, also discloses a self-cooling beveragecontainer and specifies the geometry of the heat exchanger as well asthe manufacturing and assembly process of such a device which iscompatible with the industrial constraints of high output volumes.

The beverage container described in this International Application isconstituted by a closed first can 10 containing the consumer beverageand a heat exchanger 20 and a closed second can 30 containing desiccants24. The two cans are assembled by a ring 29. Communication means 40between said two cans must be actuated by a porous spike 44 to allowimplementation of the cooling method by evaporation adsorption of thevapors of a refrigerant contained in the exchanger. These communicationmeans, a detailed illustration of which is given in FIG. 2 b, comprise aseal 66 comprising two membranes 70 and 71 arranged opposite each otherin the walls of the first and second cans of the container respectively.The porous spike 44 makes it possible to tear the seal 66 so as toconnect the desiccants reservoir 30 to the heat exchanger 20, thustriggering the evaporation reaction by adsorption and cooling thebeverage.

This document also discloses the manufacturing process of such aself-cooling beverage container and in particular the assembly stages ofthe different elements constituting the container. The assembly stage ofthe first can 10, containing the beverage and the heat exchanger 20,with the can 30 containing the desiccants is particularly delicate as itis essential to maintain a high vacuum in the desiccants reservoir 30and at the seal 66 so that the adsorption reaction can be actuatedduring tearing of the membranes 70 and 71. To this end, ApplicationWO01/11297 proposes to place a drop of oil 73 between the two membranes70 and 71 in order to guarantee a good tightness of the vacuum duringassembly of the two cans.

However, the self-cooling beverage container as well as the processdescribed in this Application WO01/11297 have certain drawbacks. Inparticular, the system of connecting the desiccants reservoir 30 to theheat exchanger 20 is not optimized. In fact, the two membranes 70 and 71each have a relatively substantial thickness which is essential inresisting the external atmospheric pressure before assembly of thecontainer. Moreover, these two membranes 70 and 71 constitute a doublethickness which requires a major rupture force. To this end, the PatentApplication specifies that the porous spike element 44 is actuated usinga screw. Moreover, the production of such a seal 66 complicates assemblyof the container, in particular with the requirement to keep theinterstice between the two membranes 70 and 71 under air vacuum, whenone of them turns relative to the other.

SUMMARY OF THE INVENTION

The aim of the present invention is overcome the drawbacks of the priorart To this end, the present invention sets out to produce aself-cooling container based on the method of cooling by evaporation andadsorption as previously described and to provide communication meansbetween the desiccants reservoir and the heat exchanger in a wall commonto said reservoir and exchanger. The communication means are constitutedby a non-return valve, i.e. one which resists a strong pressure in onedirection and opens easily in the other direction.

The non-return valve can thus resist atmospheric pressure with a highvacuum in the desiccants reservoir and can be actuated by a minimalforce directed towards the inside of the heat exchanger.

More particularly, the invention provides a self-cooling containercomprising a first cavity containing a product to be cooled, a secondcavity forming a heat exchanger and containing a refrigerant and itsvapor, a third cavity containing means of pumping by adsorption of saidvapor and means of communicating said second cavity to said thirdcavity, characterized in that the second and third cavities have acommon wall integrating the communication means, and in that saidcommunication means are constituted by a non-return valve adapted toresist the pressure exerted on the second-cavity side and opening by theaction of a force exerted on the third-cavity side.

According to one characteristic, the valve is constituted by a solidcover situated on the second-cavity side and closing an opening in thecommon wall of the second and third cavities.

According to the embodiments, the communication means also comprise avalve seal, constituted by a deformable gasket situated between thesolid cover and the common wall of the second and third cavities or by avacuum-tight and tearable foil covering the solid cover and bonded tothe common wall of the second and third cavities.

According to one characteristic, the valve is actuated by a push rodtransmitting a movement of at least one portion of the wall of the thirdcavity opposite to the wall containing the communication means.

According to a special characteristic, the push rod is an open hollowtube allowing the vapor of the refrigerant to travel inside said rod.

According to an advantageous embodiment variant, the push rod containsmeans of opening the valve in two stages, a first position of the valvedelimiting a restricted passage for the vapor of the refrigerant and asecond position of the valve developing an enlarged passage for thevapor of the refrigerant.

According to the embodiments, the ratio of the mass of the valve to thesurface area of the tube of the push rod is between 0.5 and 2 g/cm²,and/or the push rod contains a stop situated at a distance of between 2and 5 mm from the valve.

According to an advantageous embodiment variant, the second cavitycontains a liquid-gas state separation device arranged around the valve.

According to one characteristic, the second cavity is of a substantiallyconical shape such that its sectional surface decreases from base toapex.

According to one characteristic, the second cavity is delimited by thebottom of the first cavity and the cover of the third cavity.

According to the embodiments, the first and third cavities constitutetwo separate assembled cans or the first and third cavities constitutecompartments of a single can.

In one application, the container is presented in the form of a beveragecan.

The characteristics and advantages of the present invention will becomeapparent from the description which follows, given by way ofillustrative and non-limitative example, and with reference to thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, already described, is a diagram of a self-cooling beverage canaccording to one embodiment of the prior art;

FIGS. 2 a and 2 b, already described, are respectively a general diagramof a self-cooling beverage can and a detailed diagram of thecommunication means according to the prior art;

FIGS. 3 a and 3 b are schematic views of the device according to theinvention with the valve in the closed position and open positionrespectively;

FIG. 4 is a schematic view according to a first embodiment of the valveaccording to the invention;

FIG. 5 is a schematic view according to a second embodiment of the valveaccording to the invention;

FIG. 6 is a schematic view of a push rod for the implementation of thevalve according to the invention;

FIG. 7 is a schematic view of a liquid-gas state separation devicearranged in the beverage container according to the invention;

FIG. 8 is a schematic view of a push rod for the implementation of atwo-stage opening of the valve according to the invention;

FIG. 9 is a schematic view of a beverages container according to a firstembodiment of the invention;

FIG. 10 is a schematic view of a beverage container according to asecond embodiment of the invention;

FIG. 11 is a schematic view of a beverage container according to a thirdembodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the description which is given hereafter FIGS. 3 a and 3 b illustrateschematically a beverage container according to the invention. Thebeverage container according to the invention comprises a first cavity10 containing a consumer beverage to be cooled, a second cavity 20forming a heat exchanger and containing a refrigerant the evaporation ofwhich produces the cooling and a third cavity 30 containing means ofpumping by adsorption of the vapor of the refrigerant of the secondcavity 20. The first 10 and second 20 cavities have a common wall 25which constitutes a heat exchanger. This common wall advantageously hasa conical shape with ribs in order to encourage the exchange of heat byconvection in the first cavity 10.

The container according to the invention moreover requires means oftriggering the cooling reaction. This reaction is triggered byconnecting the second 20 and third 30 cavities to each other, thuscausing the evaporation of the refrigerant of the second cavity 20 thevapor of which is pumped by a desiccant contained in the third cavity30. In order to guarantee a good pumping efficiency of the desiccant, itis necessary that the third cavity 30 be assembled and closed undervacuum, with a vacuum of less than 1 mbar and preferentially less than0.1 mbar.

Thus, according to the invention, the means 40 of connecting the secondcavity 20 to the third cavity 30 are integrated in a wall 25 common tosaid cavities. It is therefore sufficient to create an opening 44 inthis common wall 25 to trigger the cooling.

According to the invention, the communication means 40 are constitutedby a non-return valve 42 closing an opening 44 in the common wall 25 ofthe second and third cavities. This valve 42 has the characteristic ofbeing able to open only towards the outside of the third cavity 30, i.e.towards the inside of the second cavity 20. The valve 42 is able toresist the pressure exerted on the second-cavity side 20 and opens bythe action of a force exerted on the third-cavity side 30. By way ofguidance, this opening force exerted on the valve 42 can be between just1 and 10 Newton.

FIGS. 3 a and 3 b illustrate more specifically the valve according tothe invention in the closed and open positions respectively.

The cooling reaction is triggered by the movement of the valve 42towards the inside of the second cavity 20. The non-return valve 42 isactuated by a push rod 45 transmitting a movement of at least oneportion of the wall 35 of the third cavity 30 opposite the wall 25comprising the communication means 40. The deformable wall 35 of thethird cavity 30 can be constituted by a dome-shaped structure resistantto the atmospheric pressure applied to the outside of the third cavity30 which is assembled and closed under vacuum. This dome-shapedstructure 35 can however be turned inwards under the action of a forcelocated at the centre of the dome, such as a force of 20 to 30 Newtonapplied to a central surface area of 1 cm². This force serves mainly toturn the dome inwards, which causes the push rod to move. The forcerequired to open the valve 42 is negligible compared with thedeformation force of the dome of the wall 35 of the third cavity 30.

FIGS. 4 and 5 illustrate schematically a first and a second embodimentof the non-return valve according to the invention. The valve 42 isconstituted by a solid cover 43 situated on the second-cavity side 20and closing an opening 44 of the common wall 25 of the second 20 andthird 30 cavities. The solid cover 43, such as a metal disk, hasdimensions which are slightly greater than those of the opening 44 ofthe common wall 25.

According to a first embodiment, illustrated in FIG. 4, thecommunication means 40 moreover comprise a valve seal 42 constituted bya deformable gasket 47, such as of vacuum grease or an elastomer,situated between the solid cover 43 and the common wall 25 of the secondand third cavities.

According to a second embodiment, illustrated in FIG. 5, thecommunication means 40 also comprise a valve seal 42 constituted of athin vacuum-tight and tearable foil 48, such as an aluminium foil{fraction (2/100)} mm thick, covering the solid cover 43 and bonded tothe common wall 25 of the second and third cavities.

The valve seal 42 offers only a weak resistance to the pressure exertedby the solid cover 43 when the valve 42 is actuated by the push rod 45.This additional weak resistance, of a few hundreds of grams, correspondssimply to the debonding of the deformable gasket 47 or to the tearing ofthe thin foil 48. The pressure prevailing in the second cavity 20, of afew tens of mbar, only adds a few tens of grams to the resistance of theseal, considering a surface area of the valve cover of less than 1 cm².

The non-return valve 42 constituting the communication means 40 of thesecond 20 and third 30 cavities of the container according to theinvention has the characteristic of opening in one direction only, fromthe third towards the second cavity.

Thus, this function of the valve 42 considerably facilitates themanufacture of the beverage container according to the invention byallowing the handling of the different elements of the container atatmospheric pressure, without requiring an excessive effort to triggerthe cooling reaction. In particular, the valve 42 remains closed if thethird cavity 30, with a cover 25 integrating the valve 42, is exposed toatmospheric pressure when this third cavity is already under vacuum.

Moreover, in the case of a pasteurized beverage with its container, theone-way opening of the valve 42 has the advantage of supporting the risein pressure in the second cavity 20 during the rise in temperature, upto approximately 80 to 90° C., required for pasteurization.

FIG. 6 illustrates schematically the push rod actuating the valve of thecommunication means of the beverage container according to theinvention. The push rod 45 is advantageously constituted by an openhollow tube which therefore allows the vapor of the refrigerant totravel inside said rod between the second cavity and the third cavity.The rod 45 can be obtained from a sheet of rolled metal in the form ofan open tube.

Upon the actuation of the valve 42 allowing the communication of thesecond and third cavities to each other, the pumping reaction of thevapor of the refrigerant starts immediately. The refrigerant boilsviolently under the action of the depression. This boiling causesprojections of drops of refrigerant which, if they enter the thirdcavity containing the desiccant, can be harmful to its efficiency.

In order to overcome this drawback, it is advantageous to integrate aliquid-gas state separation device in the second cavity 20, around thenon-return valve 42 according to the invention, as illustrated in FIG.7. The container must be positioned with the second cavity orientateddownwards during cooling.

The state separator 50 comprises a vapor deflector which is composed ofat least one wall forming baffle means 51 which imposes one or moreabrupt changes of direction on the vapor flow. The vapor molecules havea very short mean free path, of the order of a micrometre, which meansthat they can change direction very rapidly. On the other hand, thedrops of liquid have a mass such that they are entrained by theirinertia and therefore separated from the gas flow. This mechanismadvantageously allows a liquid-gas separation without major slowing ofthe vapor flow and does not therefore require the occupation of asubstantial volume.

The state-separation device 50 also comprises, in addition, a dropcollector 52 which makes it possible to redirect the liquid drops whichhave been separated from the vapor gas flow towards the bottom of thecavity of the heat exchanger 20. The collector 52 comprises a funnel andat least one discharge tube for the drops. The funnel can advantageouslycontribute to the formation of the baffle means 51 of the vapordeflector.

Preferentially, the discharge tube for the drops of the collector 52 hasa length greater than or equal to the pressure drop of the vapor in thebaffle means 51 in order to avoid the projection of drops through saiddischarge tube. This pressure drop is advantageously measured in watervolume height. Considering, for example, a pressure drop of the vapor of1 mb (corresponding to 1 cm water column height) the tube will be atleast 1 cm long.

Such a state-separation device reaches its limits however if the rate ofdischarge of the vapor is too great. When the cooling reaction istriggered, the pressure difference between the second and third cavitiesis several tens of millibars, leading to a rate of discharge of thevapor such that the state-separation device can be saturated by thedroplets of refrigerant entrained with the vapor.

In order to limit this effect, according to a variant of the invention,the non-return valve 42 is opened in two stages.

In the first position, the cover 43 of the valve 42 is kept in contactwith the tube of the push rod 45 by the overpressure of the secondcavity 20 relative to the third cavity 30. The mass of the cover 43 ofthe valve is such that it remains in contact with the push rod 45 andthus limits the passage of vapor of the refrigerant towards the thirdcavity to travel in the hollow of the rod through a limited lateralopening.

When the overpressure of the second cavity relative to the third cavitybecomes less than approximately 1 to 3 mbar, the vapor flow-rate fallsand the cover 43 of the valve 42 drops into the second cavity 20 thusreleasing a larger opening for the passage of the vapor. As mentionedpreviously, the cooling is triggered with the third cavity towards thetop of the container.

The level of overpressure, and therefore the vapor flow-rate, for whichthe full opening of the valve 42 is operated can be adjusted by the massof the valve, and more specifically of the solid cover 43. The ratio ofthe mass of the cover to the surface area of the tube of the push rodcan advantageously be between approximately 0.5 and 2 g/cm². A typicaloverpressure value can be 2 mbar with a surface area of the tube of thepush rod of 0.3 cm², i.e. a mass of the cover of the valve of 0.6 g.

In order to better control the level of opening of the first position ofthe valve 42 in the first stage of a high vapor flow-rate, it can beexpedient to create a stop 46 in the push rod 45, as illustrated in FIG.8. Advantageously, this stop 46 is situated at a distance ofapproximately 2 to 5 mm from the end of the rod in contact with thevalve cover. The restricted opening of the valve is thus ensured over aheight of 2 to 5 mm by the lateral opening of the push rod and thecomplete opening of the valve is ensured by the whole section of tube.

Apart from the functionality of a one-way opening between the cavitiesforming the heat exchanger and the desiccants reservoir, the beveragecontainer according to the invention has the advantage of allowing easyassembly.

FIGS. 9 to 11 illustrate different embodiments of such an assembly.

In particular, the second cavity 20 of the container does not requirethe production of an additional piece. The second cavity 20, forming theheat exchanger, is defined by a space delimited between the cover of thethird cavity 30 and the bottom of the first cavity 10. The second cavity20 is thus obtained during the assembly of the third cavity 30 with thefirst cavity 10, in a tight fashion.

According to a first embodiment, illustrated in FIG. 9, the first 10 andthird 30 cavities are assembled by fitting together two cylinders bybonding or brazing 60.

The fitting of the third cavity 30 to the first cavity 10 is carried outafter having arranged the cover 25 closing the reservoir of desiccant onthe third cavity 30. It will be recalled that this cover 25 integratesthe communication means 40. This cover can also be bonded or brazed 61to the inside of the cylinder forming the third cavity 30.

According to a second embodiment, illustrated in FIG. 10, the first 10and third 30 cavities of the container constitute the compartments of asingle can. The separation cover 25 between the second 20 and third 30cavities is introduced into the can and fixed by bonding or brazing 61to the walls of the can. The common wall of the first 10 and second 20cavities, forming the heat exchanger, is also introduced into the canand fixed by bonding or brazing 60, after the refrigerant has beenintroduced.

A brazing 60, 61, with tin for example, can be carried out by localizedinduction heating. Eddy currents are induced by a coil surrounding theassembly area. This coil is fed by a high-frequency alternating current.This technique allows a precise and rapid assembly.

According to a third embodiment, illustrated in FIG. 11, the first 10and third 30 cavities are assembled by crimping 62 two cylinders. Forexample, the wall common to the second and third cavities is crimped tothe wall common to the first and second cavities, the assembly beingcompleted by a cylindrical ring 63, bonded or brazed, creating thejunction between the two cylinders.

The embodiment variants described above are presented by way ofillustration but in a non-limitative fashion in order to show theflexibility of the assembly of the container according to the invention.

These embodiment variants described can moreover be combined indifferent ways.

1-15. (canceled)
 16. A self-cooling container comprising a first cavitycontaining a product to be cooled, a second cavity forming a heatexchanger and containing a refrigerant and its vapor, a third cavitycontaining means of pumping by adsorption of said vapor and means ofcommunicating said second cavity to said third cavity, characterized inthat the second and third cavities have a common wall integrating thecommunication means, and in that said communication means areconstituted by a non-return valve adapted to resist the pressure exertedon the second-cavity side and opening by the action of a force exertedon the third-cavity side.
 17. The self-cooling container according toclaim 16, wherein the valve is constituted by a solid cover situated onthe second-cavity side and closing an opening of the common wall of thesecond and third cavities.
 18. The self-cooling container according toclaim 17, wherein the communication means also comprise a valve sealconstituted by a deformable gasket situated between the solid cover andthe common wall of the second and third cavities.
 19. The self-coolingcontainer according to claim 17, wherein the communication means alsocomprise a valve seal constituted by a vacuum-tight and tearable foilcovering the solid cover and bonded to the common wall of the second andthird cavities.
 20. The self-cooling container according to claim 16,wherein the valve is actuated by a push rod transmitting a movement ofat least one portion of the wall of the third cavity opposite the wallcontaining the communication means.
 21. The self-cooling containeraccording to claim 20, wherein the push rod is an open hollow tubeallowing the vapor of the refrigerant to travel inside said rod.
 22. Theself-cooling container according to claim 20, wherein the push rodcontains means of opening the valve in two stages, a first position ofthe valve delimiting a restricted passage for the vapor of therefrigerant and a second position of the valve developing an enlargedpassage for the vapor of the refrigerant.
 23. The self-cooling containeraccording to claim 22, wherein the ratio of the mass of the valve to thesurface area of the tube of the push rod is between 0.5 et 2 g/cm². 24.The self-cooling container according to claim 21, wherein the push rodcontains means of opening the valve in two stages, a first position ofthe valve delimiting a restricted passage for the vapor of therefrigerant and a second position of the valve developing an enlargedpassage for the vapor of the refrigerant.
 25. The self-cooling containeraccording to claim 24, wherein the ratio of the mass of the valve to thesurface area of the tube of the push rod is between 0.5 et 2 g/cm². 26.The self-cooling container according to claim 22, wherein the push rodcontains a stop situated at a distance of between 2 and 5 mm from thevalve.
 27. The self-cooling container according to claim 16, wherein thesecond cavity contains a liquid-gas state separation device arrangedaround the valve.
 28. The self-cooling container according to claim 16,wherein the second cavity has a substantially conical shape such thatits sectional surface decreases from base to apex.
 29. The self-coolingcontainer according to claim 16, wherein the second cavity is delimitedby the bottom of the first cavity and the cover of the third cavity. 30.The self-cooling container according to claim 16, wherein the first andthird cavities constitute two separate assembled cans.
 31. Theself-cooling container according to claim 16, wherein the first andthird cavities constitute compartments of a single can.
 32. Theself-cooling container according to claim 16, wherein it is presented inthe form of a can for a consumer beverage.